Frequently Asked Questions

What is the first thing to check when the check engine light comes on?

• Check immediate, simple items first: a loose or missing gas cap can trigger the light and is quick to fix.
• Verify obvious fluid levels and look for visible leaks under the vehicle before driving further.
• If the light is steady and you notice no performance loss, schedule a diagnostic with Nalley Lexus Roswell for a fast, accurate scan.
• If you have a flashing light or drivability issues, stop driving and contact us — flashing often indicates a misfire that can damage the catalytic converter.

What does it mean when the check engine light comes on in a 2021 Lexus LS 500h?

• It indicates that the vehicle’s onboard diagnostics detected a fault in emissions, engine, or drivetrain systems — codes are stored in the ECU.
• Codes range from minor emissions issues to serious misfires; only a proper scan identifies the root cause.
• Having Nalley Lexus Roswell diagnose the vehicle ensures accurate fault interpretation by factory-trained technicians using Lexus-level tools.
• Repairs covered under warranty must be performed at a certified dealership to preserve coverage and ensure long-term savings.

What is the most common reason for check engine light on a 2021 Lexus LS 500h?

• Common causes include loose gas caps, oxygen sensor failures, misfires, catalytic converter efficiency alerts, and evap system leaks.
• Many issues start small but become costly if left unaddressed — early diagnosis prevents expensive downstream repairs.
• Nalley Lexus Roswell’s factory-trained team identifies root causes quickly, helping you avoid repeated visits and long-term fuel or repair costs.
• When warranty coverage applies, required repairs must be done at a certified dealership to maintain benefits and ensure genuine parts.

How long does a check engine light service take?

• Initial diagnostics typically take 30–60 minutes: we perform a full OBD-II scan, review live data, and perform a systems check.
• If further inspection or parts are required, total repair time varies — many common fixes are completed the same day.
• Nalley Lexus Roswell prioritizes efficient appointments and keeps you informed of timelines and costs for immediate and long-term savings.
• Warranty repairs are scheduled and completed by certified technicians to preserve coverage and ensure quality outcomes.

How much does a check engine light diagnostic cost for a 2021 Lexus LS 500h?

• Diagnostic fees commonly range from $80–$150 depending on the scope; Nalley Lexus Roswell provides transparent pricing and written estimates.
• Many independent repairs miss underlying causes; our dealership often costs less overall by preventing repeat work and using OEM parts.
• Choosing a certified dealer delivers immediate savings through accurate diagnosis and long-term savings via proper repair, factory parts, and warranty protection.
• Remember: repairs covered under warranty must be performed at a certified dealership to keep coverage valid and protect future resale value.